Math Circles are a form of education outreach and enrichment through which mathematicians and mathematical scientists share their passion with K-12 teachers and students. The Math Circle landscape includes two types of programs that can operate standing alone or in coordination: Math Students’ Circles and Math Teachers’ Circles. Math Circles bring K-12 students or K-12 mathematics teachers together with mathematically sophisticated leaders in an informal setting, after school or on weekends, to work on interesting problems or topics in mathematics. The Circles combine significant content with a setting that encourages a sense of discovery and excitement about mathematics through problem solving and interactive exploration. Ideal problems are low-threshold, high-ceiling; they offer a variety of entry points and can be approached with minimal mathematical background, but lead to deep mathematical concepts and can be connected to advanced mathematics.

The Math Circle movement migrated to the United States from Eastern Europe in the 1990s. Today, more than 180 Match Circles programs are operating across the country, with more than 210 Circles formed since 1994. Math Circles adopt a range of practice in terms of venue, the grade level and backgrounds of participants served, and the types of mathematical professionals who are engaged. In some, but not all settings, Math Students’ Circles and Math Teachers’ Circles affiliate their activities. Math Circles are designed to provide an easy entry point for mathematicians with limited experience working in K12 mathematics outreach.